The invention relates generally to an arrangement for and a method of processing articles, especially an arrangement for and a method of continuously developing strips and/or sheets of photosensitive material.
More particularly, the invention relates to an arrangement for and a method of regenerating a processing bath, e.g. a developing and/or fixing bath for photosensitive materials.
A known photographic developing apparatus permits continuous development of strips and/or sheets of photosensitive material to be achieved. The photosensitive material, which may vary in width and/or quantity, is passed through the apparatus by means of conveying elements.
The apparatus is provided with means for supplying a regenerating solution to each of the different baths. An arrangement for determining the amount of regenerating solution to be added to each bath includes a device for measuring the speed of the photosensitive material as well as a device for totalling the widths of the photosensitive strips and/or sheets passing through the apparatus. The latter device composes a row of sensing elements extending transversely of the direction of movement of the photosensitive material. The two devices emit signals which are combined in a control mechanism for regulating the additions of the regenerating solutions to the different baths.
The German Offenlegungsschrift No. 1 522 856 describes various methods for sensing the width of the photosensitive material.
A regenerating arrangement having a mechanism for sensing the width and length of the photosensitive material is disclosed in the German Auslegeschrift No. 1 278 240.
In addition, a regenerating arrangement of the type outlined above is known from German Pat. No. 25 57 253. The speed of the photosensitive material is sensed by a memory or storage device which is movable towards and away from the photosensitive material, and the length of the photosensitive material is calculated from the speed. A reflex light barrier is transported transverse to the direction of movement of the photosensitive material and detects the presence of photosensitive material. When the signals representing the length and width of the photosensitive material coincide, an impulse is generated and causes a dose of the respective regenerating solutions to be supplied to the corresponding baths.
The arrangement disclosed in the German Pat. No. 25 57 253 is relatively imprecise. Furthermore, the speed of the movable light barrier cannot be arbitrarily adjusted in order to improve the scanning results. Small differences in size are detected only after a certain time interval during which improper doses of the respective regenerating solutions may have been supplied to the corresponding baths.